共 25 条
- [2] Meyers-Serrin type theorems and relaxation of variational integrals depending on vector fields HOUSTON JOURNAL OF MATHEMATICS, 1996, 22 (04): : 859 - 890
- [4] ON THE APPROXIMATION OF VECTOR-FIELDS USSR COMPUTATIONAL MATHEMATICS AND MATHEMATICAL PHYSICS, 1986, 26 (05): : 89 - 91
- [6] ON APPROXIMATION BY HARMONIC VECTOR-FIELDS HOUSTON JOURNAL OF MATHEMATICS, 1994, 20 (01): : 75 - 92
- [10] APPROXIMATION OF SYSTEM OF VECTOR-FIELDS AND APPLICATIONS TO HYPOELLIPTICITY ARKIV FOR MATEMATIK, 1979, 17 (02): : 237 - 254